1. Field of the Invention
The present invention relates to blade assemblies for use in microkeratomes. In particular, the present invention is related to a ceramic blade assembly for use in microkeratomes.
2. Description of Related Art
The use of microkeratomes having blades or blade assemblies for use in ophthalmic surgery is well known in the art. Typically, the microkeratome blades and blade assemblies have been fabricated from commercially available razor-blade stock with holders of plastic materials, such as Delrin® attached to the fabricated blade. One such blade assembly is described in U.S. Pat. No. 6,051,009 to Hellenkamp, et al., which patent is herein incorporated in its entirety by reference.
While these metal, razor-blade based assemblies provide precision cuts of corneal tissue, particularly in forming a flap for LASIK (laser-assisted in-situ keratomileusis) surgery, it would be desirable to provide a microkeratome blade assembly that would not require the cleaning and polishing presently required to be performed on the metal blades during manufacture. In addition, it would be desirable to have a blade assembly that provided a very precise blade extension for operating in a microkeratome to provide an extremely precise depth of cut that is repeatable from blade to blade. This extremely precise depth of cut relies on a precise blade extension being provided in the keratome blade designed to be used with a particular microkeratome.
Other blade and blade assembly materials have been suggested in the prior art, such as plastic or ceramic or precious stone materials such as diamonds or sapphires. Examples of such patents suggesting the use of ceramic materials and other materials for microkeratome blade assemblies are U.S. Pat. Nos. 6,030,398 and 6,099,541 issued to Klopotek for surgical microtomes, U.S. Pat. No. 6,447,526 issued to Carriazo for a disposable microkeratome blade housing, and U.S. Pat. No. 6,540,760 issued to Austring, et al. for a cutting blade and cutting blade assembly. While each of these patents suggest using a cutting blade or an entire cutting blade assembly formed of ceramic material, none of the above prior art describes or discloses such a microkeratome blade assembly, let alone a microkeratome blade assembly providing a precise blade extension while also being inexpensive to manufacturer and assemble for use in known microkeratomes such as the Hansatome™ available from Bausch & Lomb Incorporated.
Therefore, it would be desirable to provide a microkeratome blade assembly made of ceramic material that provides an extremely precise blade extension and yet is relatively cheaply and easily manufactured.